%0 Journal Article
%T Active-Layer Soil Moisture Content Regional Variations in Alaska and Russia by Ground-Based and Satellite-Based Methods, 2002 through 2014
%A Reginald R. Muskett
%A Vladimir E. Romanovsky
%A William L. Cable
%A Alexander L. Kholodov
%J International Journal of Geosciences
%P 12-41
%@ 2156-8367
%D 2015
%I Scientific Research Publishing
%R 10.4236/ijg.2015.61002
%X Soil moisture is a vital
physical parameter of the active-layer in permafrost environments, and
associated biological and geophysical processes operative at the microscopic to
hemispheric spatial scales and at hourly to multi-decadal time scales. While in-situ measurements can give the highest
quality of information on a site-specific basis, the vast permafrost terrains
of North America and Eurasia require space-based techniques for assessments of
cause and effect and long-term changes and impacts from the changes of
permafrost and the active-layer. Satellite-based 6.925 and 10.65 GHz sensor
algorithmic retrievals of soil moisture by Advanced Microwave Scanning Radiometer-Earth
Observation System (AMSR-E) onboard NASA-Aqua and follow-on AMSR2 onboard
JAXA-Global Change Observation Mission¡ªWater-1 are ongoing since July 2002.
Accurate land-surface temperature and vegetation parameters are critical to the
success of passive microwave algorithmic retrieval schemes. Strategically
located soil moisture measurements are needed for spatial and temporal
co-location evaluation and validation of the space-based algorithmic estimates.
We compare on a daily basis ground-based (subsurface-probe) 50- and 70-MHz
radio-frequency soil moisture measurements with NASA- and JAXA-algorithmic
retrieval passive microwave retrievals. We find improvements in performance of
the JAXA-algorithm (AMSR-E reprocessed and AMSR2 ongoing) relative to the
earlier NASA-algorithm version. In the boreal forest regions, accurate
land-surface temperatures and vegetation parameters are still needed for
algorithmic retrieval success. Over the period of AMSR-E retrievals, we find
evidence of at the high northern latitudes of growing terrestrial
radio-frequency interference in the 10.65 GHz channel soil moisture content.
This is an important error source for satellite-based active and passive
microwave remote sensing soil moisture retrievals in Arctic regions that must
be addressed.
%K Soil Moisture
%K Active Layer
%K Radio
%K Microwave
%K Remote Sensing
%K AMSR-E
%K AMSR2
%K NASA
%K JAXA
%K Alaska
%K Russia
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53322